Antimicrobial Testing Research Articles

Preparation and characterization of a novel green cinnamon essential oil nanoemulsion for the enhancement of safety and shelf-life of strawberries

This study aimed to optimize a novel green CEO nanoemulsions (CEO NEs) and explore its physicochemical properties and the effect on the shelf-life of strawberries during storage at environmental temperature (20–25 °C). We used CEO as oil phase and tea saponin (TS) as a natural surfactant to formulate the novel green CEO NEs, and its potential as an antimicrobial agent was also investigated. The results showed that CEO NEs had a droplet size about 170 nm with uniform distribution and regularly spherical. These CEO NEs exhibited excellent storage stability, thermal stability, pH stability and centrifugal stability. The antimicrobial test indicated that the minimal inhibitory concentration and the minimal bactericidal (fungicidal) concentration of CEO NEs against Escherichia coli, Botrytis cinerea and Aspergillus flavus were 17.81 μg/mL and 35.62 μg/mL, 35.62 μg/mL and 71.25 μg/mL, 2.23 μg/mL and 4.45 μg/mL, respectively, which were significantly lower than those of pure CEO (333.75 μg/mL and 667.5 μg/mL, 667.5 μg/mL and 1335 μg/mL, 41.72 μg/mL and 83.44 μg/mL). More interestingly, after soaking strawberries in CEO NEs for 2 min, the shelf-life of strawberries can be extended to 7 days at environmental temperature, and a lower rate of weight loss and mildew were showed in the group of CEO NEs than other control groups, especially the strawberries in ultrapure water group went bad first, obviously shranked, and contaminated by molds after 3 days. The above results indicate that CEO NEs prepared in this study has great potential as a new green antimicrobial agent in fruit preservation.

Advancing Antimicrobial Efficacy of Cucumis Momordica Seeds: Nanoemulsion Application in Eurotium cristatum-Mediated Solid-State Fermentation

This study explores the enhancement of Cucumis Momordica seed powder's properties through Eurotium cristatum-mediated solid-state fermentation (SSF) and its application in nanoemulsions, emphasizing protein content, functional properties, stability, and antimicrobial activity. The protein content increased significantly from 23.28±0.23% in the control to 29.83±0.12% after 144h of fermentation. The Cucumis Momordica seed powder fermented for 96h was further analyzed for its functional properties and characterization. The water absorption capacity was increased from 0.91 to 2.56g/g, and oil absorption capacity from 0.79 to 1.16g/g. SEM and FTIR analyses revealed morphological changes and chemical profile alterations, indicating enzymatic degradation and enhanced functional properties. Nanoemulsions from fermented powder showed reduced droplet sizes (148±0.34nm to 126±0.37nm) and more negative zeta potentials (-24.5±0.12mV to -25.79±0.18mV), suggesting improved stability. Temperature stability was superior in fermented seed powder nanoemulsions, demonstrating enhanced thermal resistance. Antimicrobial tests against E. coli and S. aureus showed significantly lower MIC and MBC values for fermented powder nanoemulsions (E. coli MIC: 2.189mg/mL, MBC: 1.089mg/mL; S. aureus MIC: 1.196mg/mL, MBC: 0.459mg/mL), indicating increased antimicrobial efficacy. These results highlight the potential of SSF and nanoemulsion technology in advancing the functionality and application of Cucumis Momordica seeds as natural antimicrobial agents.

Combination of a novel bacteriophage and d-serine effectively controls Vibrio parahaemolyticus growth in seafood

Seafood is an important high-protein and low-fat food source prone to spoilage and may harbor food poisoning bacteria. Vibrio parahaemolyticus is a gram-negative halophilic bacterium that causes food poisoning. It is heat labile and can be eliminated through heating; however, V. parahaemolyticus may be present in seafood for raw consumption, such as sashimi. Recently, the use of bacteriophages or phages has been proposed as a non-thermal inactivation method for microbial control. Here, we characterized VF16, a novel phage that infects V. parahaemolyticus, and evaluated the effectiveness of the combination of VF16 with the antimicrobial amino acid d-serine in controlling V. parahaemolyticus through antimicrobial testing in broth cultures and raw scallops. The morphology of VF16 was examined using transmission electron microscopy, which demonstrated that it had a long, flexible tail characteristic of a siphovirus. Genome sequencing revealed that VF16 is a novel phage belonging to the family Demerecviridae, subfamily Ermolyevavirinae, and genus Vipunavirus. Analysis of adsorption and one-step growth curve in a liquid medium indicated that Ca2+ and Mg2+ are necessary for one or more subsequent replication processes of VF16 but are not essential for its adsorption. The combination of VF16 and d-serine completely inhibited the regrowth of V. parahaemolyticus in the liquid medium and effectively suppressed its growth in the scallop samples. No VF16-resistant mutants were isolated from the scallop samples treated with VF16 alone or in combination with d-serine. The combination of phages and d-amino acids is an effective non-thermal inactivation method for controlling foodborne pathogens.

Water-soluble polysaccharides extracted from Enteromorpha prolifera/PVA composite film functionalized as ε-polylysine with improved mechanical and antibacterial properties

The issue of environmental protection has received sustained and widespread attention. In order to reduce environmental pollution related to traditional plastics, it is an incessant demand to design novel environment-friendly food packaging materials with excellent performance. Sulfated polysaccharide extracted from the “green tide” marine pollution Enteromorpha prolifera (SPE) has been innovatively transformed into a film-forming material for better utilization. The insufficient mechanical properties and limited functionalities, however, hinder its wide application. In this study, polyvinyl alcohol (PVA) was blended to enhance its mechanical properties and ε-polylysine (ε-PL) was incorporated to endow it with antimicrobial performance. A novel and biodegradable film composed of SPE, PVA, and ε-PL was fabricated by casting method. We further determined the physicochemical properties of composited films. Mechanical performance test revealed the tensile strength of SPE-PVA-PL films increased from 5.56 MPa to 6.65 MPa and the E% increased from 128.8 % to 246.9 % compared with that of SPE-PVA films. Antimicrobial tests showed the excellent antibacterial activity of SPE-PVA-PL films against representative microbial species, Staphylococcus aureus and Escherichia coli. The results of this study suggested that the SPE-based composite film has the potential to be used as a potential food packaging and wound dressing materials.

Improvement in bioactivity, hardness and friction resistance of 3 % manganese-doped hydroxyapatite coated on alumina using radio frequency magnetron sputtering

Hydroxyapatite (HAP) is a common hard tissue implant material known for its superior biocompatibility and osteoconductivity. However, its poor mechanical strength, brittleness and slow degradation limit the applications. This study explores the enhancement of HAP mechanical properties and bioactivity by coating 3 wt% manganese-doped HAP (Mn-HAP) on another inert biomaterial alumina (Mn-HAP/Al2O3) substrates using the RF magnetron sputtering technique. Characterization of these samples was performed using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), Grazing Incidence X-ray Diffraction (GIXRD), Fourier Transform Infrared Spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) techniques. Mechanical property was assessed through Vicker's hardness and adhesion of the film was studied by scratch testing. Corrosion resistance was evaluated using Tafel plots in Ringer's solution by Electrochemical analyser (ECA), and dielectric properties were measured using Impedance analyser. Biocompatibility was examined by wettability tests, thrombogenicity, antioxidant test, antimicrobial investigation and MTT [3-(4, 5-dimethythiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. The results show that Mn-HAP/Al2O3 coatings exhibit superior properties as compared to pure HAP, alumina, and HAP/Al2O3. Mn-HAP showed enhanced crystallinity and grain refinement, leading to improved hardness of 1198 HV for Mn-HAP/Al2O3 as compared to 39.84 HV for pure HAP and 1028 HV for HAP/Al2O3. The friction coefficient was found to be best in the Mn-HAP/Al2O3 sample. Corrosion rate significantly decreases in Mn-HAP/Al2O3 (1.63 ± 0.28) mmpy after coating on alumina. In vitro studies demonstrated enhanced cell attachment, proliferation, and differentiation after Mn-HAP coating on alumina. Antimicrobial tests revealed improved resistance against E. coli and S. aureus, with Mn-HAP/Al2O3 showing a larger zone of inhibition. The study concludes that 3 wt% Mn-HAP coatings deposited by RF magnetron sputtering hold great promise for enhancing the performance and longevity of hard tissue implants, paving the way for advanced biomedical applications.

Biogenic synthesis of porous CuO nanoparticles: Synergistic effects in photocatalytic dye degradation and electrochemical energy storage applications

This study explores the biogenic synthesis of CuO nanoparticles functionalized with Solanum nigrum, using Acalypha indica leaf extract as a reducing agent. The biogenically synthesized CuO nanoparticles were comprehensively characterized by various analytical techniques, involves X-ray diffraction analysis (XRD), BET surface area analysis (BET), energy-dispersive X-ray spectroscopy (EDAX), X-ray photoelectron spectroscopy (XPS), UV–Visible spectral analysis (UV), Fourier transform infrared spectroscopy (FTIR), fluorescence spectroscopy, photocatalytic degradation, antimicrobial assay, cytotoxicity assay, electrochemical analysis, and linear sweep voltammetry studies. The XRD analysis revealed end centered monoclinic phase with a 10 nm average crystalline size. BET analysis showed a mesoporous structure with a surface area of 11.54 m2/g. XPS and EDAX confirmed the presence of Cu2+ and O2− ions. SEM and TEM images indicated spherical, and porous nanostructures. UV–Visible spectroscopy identified an active optical range of 508–518 nm (2.40–2.45 eV), suggesting potential photocatalytic activity. The photocatalytic degradation efficiencies of Methylene blue (98.8 %) and Rhodamine B (95 %) were achieved after 100 min of irradiation. Antimicrobial tests demonstrated effectiveness against Staph. aureus, E. coli, Shigella flexneri, and Candida tropicalis. The nanoparticles exhibited notable cytotoxicity against colorectal cancer cells with IC50 values of 58.66 μg/ml and 66.78 μg/ml. Additionally, a symmetric supercapacitor electrode using these nanoparticles achieved a specific capacitance of 375 Fg−1 at the current density of 1 Ag−1. This research underscores the versatile applications of biogenic CuO nanoparticles in photocatalysis, antimicrobial treatments, cancer therapy, and energy storage.

Green synthesis and characterization of TiO2 and Ag-doped TiO2 nanoparticles for photocatalytic and antimicrobial applications

TiO2 and Ag-doped TiO2 nanoparticles were synthesized using lemon grass plant leaf extract via a greener co-precipitation method. Plant biomolecules facilitated nanoparticle production, ensuring stability. Characterization involved XRD, FE-SEM, XPS, FT-IR, EDX, UV-DRS, HR-TEM and UV–Vis spectroscopy analyses, revealing tetragonal and cubic structures for TiO2 and Ag-TiO2, with average sizes of 11.96 and 41.8 nm, respectively. FT-IR confirmed characteristic bands, FE-SEM and HR-TEM analysis reveal that Ag-doped TiO2 nanoparticles primarily form irregular agglomerations, with interplanar spacings of 0.362 nm for the anatase (220) plane and 0.235 nm for the silver (111) plane and EDX determined elemental composition. UV–DRS calculated band gap values (3.3 eV for TiO2, 0.9 eV for Ag-TiO2). Photocatalytic performance against methylene blue dye under sunlight indicated higher degradation by Ag-TiO2 (96.96 %) than TiO2 (77.77 %). Antimicrobial testing showed superior activity of Ag-TiO2 over TiO2.

Geographic differences in susceptibility profiles of potential non-class B carbapenemase-producing Enterobacterales isolates against ceftazidime-avibactam, meropenem-vaborbactam, colistin, amikacin, gentamicin, and tigecycline: Data from the Antimicrobial Testing Leadership and Surveillance, 2018–2022

To evaluate the susceptibility profiles of regional meropenem-resistant (MEM-R) potential non-class B carbapenemase-producing Enterobacterales (CPE) isolates (without confirmation by phenotypic tests) against important antibiotics, we extracted data from the 2018-2022 Antimicrobial Testing Leadership and Surveillance. This data included susceptibility information of MEM-R potential non-class B CPE isolates against indicated antibiotics - amikacin [AMK], gentamicin [GM], ceftazidime-avibactam [CZA], colistin [CST], meropenem-vaborbactam [MVB], and tigecycline [TGC] - from sepsis patients hospitalized in ICUs across six major regions. Carbapenemase-encoding genes of the tested CPE isolates, determined by multiplex PCR and Sanger sequencing, were also analyzed. Susceptibility breakpoints recommended by CLSI 2024 and US FDA criteria (for TGC only) against Enterobacterales were employed. A total of 1,500 potential non-class B CPE isolates (89% of which were Klebsiella pneumoniae) were tested globally. Resistance rates to AMK and GM against the evaluated isolates were statistically higher in Africa/the Middle East, Europe, and India compared to other regions. A similar pattern was observed in the susceptibility of these potential CPE isolates to CZA and MVB. High CST resistance rates were noted in Asia, Latin America, and Europe (29%-35%). Furthermore, the proportions of potential CPE isolates carrying genes encoding blaOXA variants were notably higher among the tested CPE isolates in India, Europe, and Africa/the Middle East regions (99.2%, 53.3%, and 96.7%, respectively) compared to other regions. Trends in resistance to important antibiotics among potential non-class B CPE isolates warrant close monitoring.

Bismuth-gold nanohybrid based nano photosensitizer to combat antimicrobial resistance

Antimicrobial resistance (AMR) leads to a decrease in the adequacy of antimicrobial agents and an increase in the rate of adverse effects and mortality. The main objective of this project is to investigate the synergistic effect of BiAu@NCLin-T1 and its substructures as an antimicrobial photodynamic therapy (aPDT) agent to combat microbial resistance. In addition, the effect of photothermal therapy (PTT) on some of the designed nanostructures at a temperature of 40 °C was also tested. The antimicrobial test was carried out using the growth curve method against Escherichia coli and Staphylococcus aureus. Computational methods were used to investigate the stability and entropy of oligonucleotide sequence structures. Various analyses were performed to identify the nanostructures, including Ultraviolet–visible (UV–vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS) and fluorescence analysis. The BiAu@NCLin-T1 appeared the significant aPDT impact against the gram-negative E.coli strain at two distinctive oligonucleotide concentrations (1, and 1.5 micromolar (µM)). Based on the results, the outlined nanostructures can act as a photosensitizer (PS), a photothermal treatment (PTT) agent, and an antimicrobial agent to combat resistant bacteria.

Formulation and Evaluation of Antibacterial and Anti-Inflammatory Emulgel Containing Eugenia caryophyllus Buds Extract

ABSTRACT: Background: Eugenia caryophyllus is a valuable aromatic spice used in household cooking. Traditional healers frequently employ the plant, which is said to have therapeutic qualities, in herbal concoctions to treat a variety of illnesses and conditions. Objective: Eugenia caryophyllus clove buds have antibacterial, analgesic, and anti-inflammatory properties. The formulation of clove emulgel and its assessment using a variety of evaluation criteria were the main objectives of the current study. Clove emulgel was evaluated for its anti-inflammatory and anti-microbial properties. Materials and Procedures: We extracted and assessed the oils from Eugenia caryophyllus buds for phytochemical testing using solvents such as methanol, ethanol, petroleum ether, and N-hexane. We prepare emulgel and test it for spreadability, pH, and other organoleptic characteristics. We used egg albumin denaturation as a protein to measure the in vitro anti-inflammatory efficacy. We tested the antibacterial susceptibility using the agar-well diffusion method. Results: Alkaloids, saponins, tannins, steroids, carbohydrates, and glycosides were the phytochemical components found in clove bud extract. Physical factors such as color, consistency, and state—such as semi-solid, smooth, and brownish-gummy—are included in this category of evaluation parameters. The emulgel's pH was 5.35, its spreadability ranged from 1.6 to 2.5 cm, and no phase separation was noticed while the emulgel was stored. An in vitro anti-inflammatory test (spectroscopy method) and an antimicrobial test (zone of inhibition) were used to evaluate the anti-inflammatory activity of emulgel. Comparing clove oil emulgel to a typical medication, these evaluations found that it demonstrates strong anti-inflammatory and antibacterial resistance. Conclusion: In conclusion, Clove Buds Emulgel has demonstrated antibacterial activity against both gram-positive and gram-negative bacterial strains. Emulgel demonstrated the inhibitory response percentage in relation to the standard. This validates the roles that E. caryophyllus has been shown to play in protecting human health. This innovative emulgel mixture was applied to arthritis to lessen microbial infection and joint discomfort. In addition, more preclinical and clinical trials will be needed for this research in order to successfully commercialize the emulgel formulation for the treatment of inflammation and antimicrobial activity.

Valorization of chitosan for sustainable soap production: Development, performance evaluation, and hygiene applications

This study investigates a new method for making soap by using chitosan (CH) obtained from discarded cephalopod waste. This strategy aims to tackle the environmental issues related to trash disposal. Low molecular weight chitosan (LMWCH) was developed by extracting chitin, converting into chitosan and subjecting it to gamma irradiation for reducing the molecular weight. The chitosan has a molecular weight of 982 Da, making it well-suited for being included in soap compositions and providing strong anti-microbial activity. The soap that was produced demonstrated desirable attributes, such as a moisture content of 17.13%, a pH level of 9, and a stable fatty acid content, indicating its potential for successful commercial use. The soap had significant antibacterial activity against common pathogens such as Methicillin Resistant Staphylococcus aureus (MRSA) and Candida albicans ( C.albicans). After 36 h, it produced zones of inhibition measuring 7.7 ± 1.05 mm and 8.4 ± 0.5 mm respectively. The research’s reliability is based on its meticulous experimental technique, which included comprehensive characterization of both the chitosan derivative and the final soap product. Moreover, conducting antimicrobial testing on widely recognized pathogens enhances the credibility of the soap’s possible practical uses in hygiene goods. Overall, this study underscores the feasibility of utilizing waste materials for sustainable soap production while offering potential antimicrobial benefits, thus contributing to both environmental conservation and public health.

Fabrication of kenaf fiber reinforced boron carbide fillers embedded epoxy matrix composite – An antimicrobial and structural analysis

This study investigates the incorporation of boron carbide (B4C) filler particulates into a kenaf fiber-reinforced epoxy matrix to explore its potential in lightweight applications, focusing on antimicrobial effectiveness, mechanical integrity, thermal properties, and microstructural characteristics. The composite material was formulated by blending varying seven different concentrations of boron carbide (0–50 g) and kenaf fibers (KFs) with an epoxy resin, aiming to achieve a balance between mechanical strength and minimal weight. Antimicrobial test revealed that the composite material, consisting of kenaf fiber reinforced with B4C particulates, exhibited significant antibacterial activity against common pathogens. Mechanical testing indicated that the addition of boron carbide and kenaf fibers significantly improved the tensile strength and flexural rigidity of the composites. Specifically, enhancements in tensile strength and flexural modulus were quantitatively analyzed, showing notable increases compared to the base epoxy resin. Scanning Electron Microscopy (SEM) was employed to examine the fracture surfaces following mechanical testing, revealing improved interfacial bonding between the kenaf fibers and the epoxy matrix due to the presence of boron carbide. This microscopic analysis also highlighted areas where stress distribution was optimized, contributing to the composite's enhanced mechanical properties.

Crosslinking gelatin with robust inherent antibacterial natural polymer for wound healing

Gelatin-based biomaterials are widely acknowledged as a promising choice for wound dressings, given their similarity to the extracellular matrix and biocompatibility. However, the challenge of cross-linking gelatin while preserving its biocompatibility and cost-effectiveness persists. This study aimed to enhance the properties of gelatin by incorporating the oxidized lignosulfonate (OLS) biopolymer as an inexpensive and biocompatible natural material. The polyphenolic structure of OLS acts as both a cross-linking agent and an antibacterial component. The OLS/gelatin films were prepared using a casting method with varying weight ratios (0.1, 0.2, 0.3, 0.4, and 0.5 w/w). FTIR analysis confirmed the formation of Schiff-base and hydrogen bonds between gelatin and OLS. The resulting films exhibited enhanced mechanical properties (Young's modulus ∼40 MPa), no cytotoxicity, and excellent cell adhesion and morphology. Antimicrobial tests showed significant activity against Escherichia coli and Staphylococcus aureus, with higher activity against S. aureus (17 mm inhibition zone and 99 % bactericidal rate). In vivo studies in a mouse model demonstrated that the gelatin/0.2OLS dressing significantly improved wound healing, including re-epithelialization, collagen formation, inflammation reduction, and blood vessel density, compared to untreated wounds. These findings suggest that the synthesized novel gelatin/OLS wound dressing has promising healing and antibacterial properties.

Fabrication of injectable, adhesive, self-healing, superabsorbent hydrogels based on quaternary ammonium chitosan and oxidized pullulan

Injectable hydrogels, which are polymeric materials that are characterized by their ability to be injected in a liquid form into cavities and subsequently undergo in situ solidification, have garnered significant attention. These materials are extensively used in a range of biomedical applications. This study synthesized several injectable composite hydrogels through the mild Schiff base reaction while imposing different concentrations of quaternary ammonium chitosan and oxidized pullulan. Subsequent characterizations revealed a consistent and coherent porous structure within the hydrogels with smooth inner walls. The hydrogels were also determined to possess good adhesion, mechanical properties, self-healing ability, and injectability. Furthermore, antimicrobial tests against Escherichia coli and Staphylococcus aureus demonstrated antibacterial properties, which improved with increasing concentrations of quaternary ammonium chitosan. Co-culturing with skin fibroblasts demonstrated that the injectable hydrogels exhibited favourable biocompatibility and the capacity to boost cellular activity, thus underscoring its potential for use in biomedical applications.

Preparation of Zinc Oxide Nanoparticles and the Evaluation of their Antibacterial Effects.

Nosocomial bacterial infections have become increasingly challenging due to their inherent resistance to antibiotics. The emergence of multidrug-resistant bacterial strains in hospitals has been attributed to the extensive and varied use of antibiotics, further exacerbating the problem of antibiotic resistance. Metal nanomaterials have been widely studied as an alternative solution for eradicating antibiotic-resistant bacterial cells. Metallic nanoparticles attack bacterial cells through various mechanisms, such as the release of antibacterial ions, generation of reactive oxygen species, or physical disruption, against which bacteria cannot develop resistance. Among the actively researched antimicrobial metal nanoparticles, zinc oxide nanoparticles, which are FDA-approved, are known for their biocompatibility and antibacterial properties. In this study, we focused on successfully developing a precipitation method for synthesizing zinc oxide nanoparticles, analyzing the properties of these nanoparticles, and conducting antimicrobial tests. Zinc oxide nanoparticles were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), ultraviolet/visible spectroscopy, and X-ray diffraction (XRD). Antibacterial tests were conducted using the broth microdilution test with the multidrug-resistant strains of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. This study demonstrated the potential of zinc oxide nanoparticles in inhibiting the proliferation of antibiotic-resistant bacteria.

Physicochemical Characterization, Rheological Properties, and Antimicrobial Activity of Sodium Alginate-Pink Pepper Essential Oil (PPEO) Nanoemulsions.

Essential oils (EOs) have antimicrobial properties, but their low solubility in water and strong flavor pose challenges for direct incorporation into food, as they can negatively impact organoleptic properties. To overcome these issues, strategies such as oil-in-water (O/W) nanoemulsions have been developed to improve EO dispersion and protection while enhancing antimicrobial efficacy. The objective of this study was to create sodium alginate-pink pepper essential oil (PPEO) nanoemulsions using microfluidization. Various formulations were assessed for physicochemical, physical, and antimicrobial properties to evaluate their potential in food applications. The microfluidized emulsions and nanoemulsions had droplet sizes ranging from 160 to 443 nm, polydispersity index (PdI) ranging from 0.273 to 0.638, and zeta potential (ζ) ranging from -45.2 to 66.3 mV. The nanoemulsions exhibited Newtonian behavior and remarkable stability after 20 days of storage. Antimicrobial testing revealed effectiveness against Staphylococcus aureus and Listeria monocytogenes, with minimum inhibitory concentrations (MIC) of 200 µg/mL for both microorganisms and minimum bactericidal concentrations (MBC) of 800 µg/mL and 400 µg/mL, respectively, proving that encapsulation of PPEO in nanoemulsions significantly increased its antibacterial activity. These results present the possibility of using PPEO nanoemulsions as a more effective natural alternative to synthetic preservatives in food systems.

Cytotoxic and antibacterial compounds from Schinus terebinthifolia Raddi fruits

Chromatographic procedures of extracts of Schinus terebinthifolia Raddi fruits afforded (Z)-masticadienoic (1) and 3β-masticadienolic (2) acids, tetrahydroamentoflavone (3), and 4-O-methyl gallic acid (4). Addicionally, the derivative 6-oxo masticadienoic acid (1a) was prepared by an allylic oxidation. The chemical structures of obtained compounds were elucidated by spectrometric data analyses. Furthermore, both the semi-synthetic derivative and the metabolites were subjected to in vitro cytotoxicity against the A549 human lung cancer cell line, as well as antimicrobial activity tests. Compounds 2 and 1a exhibited cytotoxicity towards A549 cells with IC50 values of 20.13 and 6.11 µM, respectively. In the tests against pathogens, the CHCl3 and EtOAc soluble fractions of MeOH extract along with the pure compounds, exhibited antibacterial activity against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Except for 4-O-methyl gallic acid, the other pure compounds showed inhibitory microbial activities with MIC values ranging from 0.25 μg/mL to 25 μg/mL doses.

Chemical Constituents and their Nanoemulsion Properties of Ethyl Acetate Crude Extract from Black Galingale Rhizome

Black galingale is a medicinal plant that has medicinal properties. The major constituents found in black galingale rhizomes are flavonoids, which display antioxidant activities. Therefore, in this research, the focus is to isolate and structurally determine bioactive compounds from the ethyl acetate extract of black galingale rhizomes and evaluate their antioxidant and antimicrobial activity, The black galingale rhizomes were extracted by maceration using ethyl acetate as a solvent. the compounds were isolated by column chromatography using hexane: ethyl acetate as an eluent solvent system. The isolated compounds were examined and characterized using FT-IR, UV-Vis, and NMR techniques, examined antioxidant activity by DPPH assay, and antimicrobial activity. From the extraction of ethyl acetate extract, it was found that 4 pure flavonoid compounds could be extracted. The FT-IR spectral data of 4 compounds showed a unique vibration corresponding to OH stretching, CH stretching, C=O stretching, C=C stretching of an aromatic ring, and C-O-C bond. Antioxidant activity testing by DPPH assay found 5-hydroxy-3,7-dimethoxyflavone (1) to have the highest antioxidant activity at 73.79% compared to the standard Trolox with 133.37±1.60 mM. Antimicrobial activity testing found that 3,5,7-trimethoxyflavone (3) showed the best growth inhibition activities against B. megaterium and S.aureus, Moreover, it studies the nanoemulsion properties of 5-hydroxy-3,7-dimethoxyflavone (1) was found stable with a nanoparticle size of 21.1 nm, a zeta potential of-49.7 mV, and has PDI of 0.227. Therefore, this research shows that the extract from black galingale rhizome could be used as an active ingredient in the cosmetics industry.

Characterization of Amnion-Derived Membrane for Clinical Wound Applications.

Human amniotic membrane (hAM), the innermost placental layer, has unique properties that allow for a multitude of clinical applications. It is a common misconception that birth-derived tissue products, such as dual-layered dehydrated amnion-amnion graft (dHAAM), are similar regardless of the manufacturing steps. A commercial dHAAM product, Axolotl Biologix DualGraft™, was assessed for biological and mechanical characteristics. Testing of dHAAM included antimicrobial, cellular biocompatibility, proteomics analysis, suture strength, and tensile, shear, and compressive modulus testing. Results demonstrated that the membrane can be a scaffold for fibroblast growth (cellular biocompatibility), containing an average total of 7678 unique proteins, 82,296 peptides, and 96,808 peptide ion variants that may be antimicrobial. Suture strength results showed an average pull force of 0.2 N per dHAAM sample (equating to a pull strength of 8.5 MPa). Tensile modulus data revealed variation, with wet samples showing 5× lower stiffness than dry samples. The compressive modulus and shear modulus displayed differences between donors (lots). This study emphasizes the need for standardized processing protocols to ensure consistency across dHAAM products and future research to explore comparative analysis with other amniotic membrane products. These findings provide baseline data supporting the potential of amniotic membranes in clinical applications.

Experimental study on the use of green antimicrobial and plasticized agents during the lining of oil paintings with gelatinous materials

Purpose This paper aims to assess the efficiency of emulsified essential oils in glycerol as eco-friendly antimicrobial and plasticized agents added to the biopolymer of gelatin for lining historical oil paintings on canvases. Design/methodology/approach Cedar oil, cinnamon oil and their mixtures were emulsified in glycerol and incorporated into gelatin adhesive as green biocides and plasticizers. Physical, biological, chemical and mechanical tests were conducted on experimental mock-ups to assess the gelatin-based adhesive formulations for the reinforcement of canvas supports. Scanning electron microscope, colorimetric measurements, antimicrobial activity test, attenuated total reflection-Fourier transform infrared spectroscopy, tensile strength and elongation tests were carried out on the mock-ups before and after the artificial aging. Findings The formulations of gelatin-based adhesive with cinnamon and cinnamon-cedar mixture emulsified in glycerol proved their efficiency on the antimicrobial activity test, chemically delaying the decomposition of gelatin and accordingly providing compatible mechanical properties. Gelatin-based adhesive with emulsified cinnamon oil showed a slight yellowing that was quite improved with the mixture of the cinnamon-cedar-based adhesive formulation. Originality/value This study promotes a green approach to lining historical oil paintings by developing green formulations from bio-based origins that minimize the shrinkage and microbial infection of gelatin for lining paintings.